IPSF: Mapping litter beetle movement
Darkling beetles serve as a mechanical vector for bacteria, viruses and other pathogens
By: [Excerpts of a presentation at the 2026 International Poultry Scientific Forum]
The litter beetle (Alphitobius diaperinus Panzer, 1797) and its larvae, the lesser mealworm, are common darkling beetles in poultry environments. They serve as a mechanical vector for Salmonella, Marek’s disease virus, avian influenza virus, and other pathogens. In addition, beetles damage insulation, contaminate feed, and reduce feed efficiency when eaten by the birds. Currently, there is little knowledge of how far and fast litter beetles travel, which would be valuable information for control programs.
Joseph A. Adeyinka and colleagues at Auburn University and Mississippi State University, USA, mapped A. diaperinus distribution and movement in a laboratory model and in broiler houses. Locomotion trials showed that single beetles fled from their point of release, traveling on average 62.5 cm (24.6 inches) within 10 minutes. Group movement was density-dependent, with beetles released in groups of 30 beetles traveling farther than beetles released in groups of 10 beetles.
For field data, sampling was conducted across four broiler houses over a 12-month period at Auburn University’s Charles Miller Farm. A total of 26 cylindrical PVC pipe traps were positioned equidistantly within and around the litter zones in Houses 1A, 2, 4A, and 4B. Traps were inspected weekly to record beetle capture numbers. Trap data showed high beetle concentrations indoors in all four sampled houses.
The highest beetle densities were consistently observed in House 1A and House 2, particularly within active litter zones, while House 2 exhibited moderate fluctuations corresponding to bird placement and removal cycles. No beetles were detected in outdoor or perimeter traps, indicating confinement to litter microhabitats.
Seasonal variations revealed that captures peaked during summer and early fall, declining in winter as ambient temperatures decreased, reflecting a strong environmental influence on beetle activity and movement.
Fewer than 30% of ~2,500 marked beetles were recaptured by day 3, indicating rapid dispersal or concealment in litter. Most recaptures occurred in littered pens, with limited movement across open areas. Overall, A. diaperinus remains confined to litter microhabitats yet spreads quickly within houses, underscoring the need for continued ecological mapping to guide sustainable control strategies on broiler farms.
15 June 2026
3
minute read
